Most conventional optical scanning systems are designed specifically to read optical codes such as one-dimensional barcode symbols. Typical conventional scanning systems generate one or more beams of laser light which reflects off a barcode symbol and back to the scanning system. The system obtains a continuous analog waveform corresponding to the light reflected by the code along one or more scan lines of the system. The system then decodes the waveform to extract information from the barcode. A system of this general type is disclosed, for example, in U.S. Pat. No. 4,251,798, assigned to Symbol Technologies, Inc. A beam scanning system for detecting and decoding one and two dimensional barcodes is disclosed in U.S. Pat. No. 5,561,283, also assigned to Symbol Technologies, Inc.
Advantageously, barcodes and other optical codes can also be read employing imaging devices. For example an image sensor may be employed which has a two dimensional array of cells or photo sensors which correspond to image elements or pixels in a field of view of the device. Such an image sensor may be a two dimensional or area charge coupled device (CCD) and associated circuits for producing electronic signals corresponding to a two dimensional array of pixel information for a field of view. An “Imaging Engine And Method For Code Readers” is disclosed in a patent application so titled to Correa et al., assigned to Symbol Technologies, Inc. and filed on Jun. 12, 1998 which is hereby incorporated by reference. Many scanners in use today are deployed in handheld units which may be manually pointed at the target. Often an individual scanner is a component of a much larger system including other scanners, computers, cabling, data terminals and data displays. Applicants have discovered that imaging optical code readers, particularly when used in such systems, may be adapted to have new, non-code-reading functions.
Accordingly, it is a general object of the present invention to provide imaging systems which can be employed for code reading and for a variety of functions other than optical code reading.
Further, it is an object of the present invention to adapt imaging code readers for use in video displays, surveillance and detection of physical parameters of target objects.
Various lens systems have been developed for optical code readers. Applicants assignee, Symbol Technologies, Inc. has developed bi-stable high speed zone collection systems for barcode scanners. Systems which employ lens structures moveable into the input optical path of the scanner (drop-in optics) are disclosed in U.S. patent application Ser. Nos. 08/627,167 and 08/627,168 filed Apr. 3, 1996 to Li et al. A lens structure for an imaging code reader is disclosed in the above-mentioned Correa et al. patent application. Conventionally, code reader lens systems are designed to provide a depth of field, focus and monochrome detection particularly adapted for code reading.
It is an object of the present invention to provide a simply and inexpensively fabricated objective lens system for an optical code imaging engine.
It is another object of the present invention to provide objective lens systems enabling an imaging optical code reader to be used effectively for both code reading functions and for non-coding reading functions such as color video displays and detection of physical parameters associated with a bar-coded object or its environment.
It is another object of the present invention to provide an imaging optical code reader with a field of view and working depth of view appropriate to the signal processing and decoding capabilities of the reader and with other optical fields and focal depths for other video functions.
In a number of businesses, in particular in transportation and food retail, it is desirable to decode a barcode and to determine the dimensions or size (Volume) and/or the weight of a package or item. Presently, multiple instruments and steps are required to obtain these parameters.
It is a further object of the present invention to use an imaging optical code reader system to determine such parameters.
Some or all of the objects previously described may be achieved in a single optical code reading engine or system. With the addition of appropriate control circuitry and data processing software, a system may be constructed serving the object of producing a compact, inexpensively fabricated imaging system for performing new video and image analysis functions.
These and other objects and features of the invention will be apparent from this written description and drawings.